As a general method for displaying optical performances of a lens, for example, a method described in Patent Document 1 is known. In this method, first, a predetermined sectional direction in a refractive surface of the lens is specified. After this, two evaluation indicators as an astigmatism and a power error (curvature of field) are used as the optical performances in the sectional direction, and are displayed on one longitudinal aberration graph. The longitudinal aberration graph is a graph which displays longitudinal aberration of the lens along a meridian. The method for displaying the optical performances of the lens by the longitudinal aberration graph is preferably used for evaluation of an axially symmetrical lens such as a camera lens or the like, or a spectacle lens.
Patent Document 1: Japanese Patent Laid-open No. Sho 58-24112
However, some spectacle lenses such as a single vision aspherical lens, an astigmatic lens, a progressive-power lens, or the like are not axially symmetrical. When the optical performances of the spectacle lenses which are not axially symmetrical are displayed on the longitudinal aberration graph, only the optical performances in a specified direction along the meridian can be seen. Therefore, the optical performances of an entire axially asymmetric spectacle lens are not fully evaluated. Incidentally, it is also thought that an aberration graph along a direction other than the meridian can be prepared and displayed; however, such an aberration graph is not realistic because it is numerously required and hard to understand.
Furthermore, in the aforementioned display method, when the longitudinal aberration graphs of two different lenses are compared, especially when diameters of these lenses are different, there is a problem that it is difficult to quantitatively compare the optical performances as the entire lenses.
Moreover, in the aforementioned display method, there is a problem that those who do not have technical knowledge of the lens do not instinctively grasp the optical performances of the lens from the longitudinal aberration graphs.
An object of the present invention is to provide a method for displaying optical performances preferably applicable to also the axially asymmetric spectacle lens. Furthermore, an object of the present invention is to appropriately and easily conduct a comparison of the optical performances of the lenses having different design conditions such as the diameter or the like. Furthermore, an object of the present invention is to quantitatively evaluate the optical performances as the entire lens. Furthermore, an object of the present invention is to display the optical performances of the spectacle lens also for those who do not have the technical knowledge to instinctively and easily understand.